Apparatus for acidizing wells



Aug. 13, 1957 R. G. GoLDlNGl-:R 2,802,537

APPARATUS FOR ACIDIZING WELLS Filed Nov. 4, 1954 ATTE! RN EYS limited States Patent APPARATUS FOR ACIDIZING WELLS Robert G. Goldinger, Hays, Kans.

Application November 4, 1954, Serial No. 466,864 1 Claim. `(Cl. 166-224) This invention relates to means for acidizing wells, and particularly oil wells, by increasing the well bore with acid and by reversing the circulation of the acid whereby the acid is adapted to be used until it is substantially spent. In particular this invention relates to a vertically disposed tube extended downwardly through a well casing with a nozzle having jets in the sides on the lower end and with means for forcing the acid downwardly through the tube whereby it is projected through jets against the formation and returned to vthe well `casing and wherein the direction of flow of the acid may be reversed so that it may be forced downwardly `through the well casing and returned through the tube to a storage tank.

The purpose of this invention is to provide means for acidizing a well whereby direction of flow of the acid into the well is adapted to be reversed so that the acid may be, selectively, forced downwardly through a tube in the center of the well casing and returned around the tube or 'forced downwardly through the well casing around the tube and returned through the tube.

Various methods and devices have been provided for pressurizing and forcing acid7 chemicals, and other materials into a well casing or into an area below the casing, however, although such devices locate acid areas in wells and remove water and other particles from sand and the like, introducing the fluid and particularly acid into the well by conventional means does not increase the well bore or enlarge the formation at the lower end of the casing. With this thought in mind, this invention contemplates a head having radially disposed jets therein with an inlet passage in the lower end and means for supplying fluid, such as acid to the head through a tube extended downwardly through a well casing whereby with the head positioned on the lower end of the tube acid is discharged through the jet openings in side walls thereof against the formation, tearing down the walls of the formation.

The object of this invention is, therefore, to provide an acid projecting head on the lower end of a tube in a well casing and means for ultimately supplying acid and other uids to the interior of the head whereby the liuid is returned around the tube; or to the lower end of the well casing through the area around the tube and between the tube and the well casing the uid being returned through the tube.

Another object of the invention is to provide a network of supply pipes and valves in combination with a pump and reservoir whereby by opening and closing the valves the direction of travel of the uid through the tube and well casing may be reversed.

A further object of the invention is to provide an improved method for acidizing wells for the purpose of increasing the well bore in which the device is of a simple and economical construction.

With these and other objects and advantages in view, `the invention embodies a well casing having a packing gland at the upper end and an opening in one side, a

Y 2,802,537 `Patented Aug. 13, 1957 ICC tube extended downwardly through the packing gland and below the lower end of the casing, a head having jet openings in side walls thereof and an inlet opening in the lower end positioned on the lower end of the tube, a reservoir, a pump and means for connecting the tube and well casing to the reservoir and pump whereby the discharge of the pump is adapted to be connected, selectively, to the tube or casing and the return connections from both the tube and casing are adapted to be connected to the reservoir.

Other features and advantages of the invention will appear from the following description, taken in connection with the drawing, wherein: j

Figure l is an elevational view of the improved acid supplying apparatus showing the device connected to the upper `end of a well casing with a 'tube thereof extended' downwardly through the casing and with the casing and surrounding part of the soil being shown in section.

Figure 2 is a vertical section through the head on the lower end of the tube positioned in the well casing, the

head `being shown on anienlarged scale and being posi-j tioned in a cavity in a well formation. l

Referring now to the drawing, wherein like reference characters denote corresponding parts, the improved method for acidizing wells of this invention includes a valve head 10 mounted on `the lower end of a tube 11, a packing gland 12 positioned on -the upper end of a well casing 13 and through which the tube 11 extends, a pump 14, to the discharge of which the tube 11 is connected through a fitting 15, a valve 16 in a connection 17 between the fitting 15 and tube 11, a reservoir 18 having an inlet fitting 19 connected to one side with a nipple 20, a return connection 21 having a valve 22 therein extended from the fitting 19 to a fitting 23 in the connection 17, and a discharge connection 24 having a valve 25 therein connecting the fitting 24 to` a fitting 26 in a connection 27 which extends from a boss 28 on the gland housing 12 to the fitting 19 on the nipple of the tank 18. The connection 27 is also provided with a valve 29 and the tank 18 is provided with a return connection 30 having a valve 31 therein through which uid is supplied tothe pump 14.

The head 10 is provided with a cylindrical body having an internally threaded hub 32 and the lower end of the tube 11 is threaded into the hub, providing means for supporting the head on the lower end of the tube and, as illustrated in Figure 2, the body of the head is provided with radially disposed apertures 33 through which acid, or the like, is discharged against the formation, as indicated by the numeral 34.

The lower end of the head 10 is provided with a flange 35 to which a perforated cage or screen 36 is attached with bolts 37, the bolts extending through openings in the flange 35 and being threaded into a flange 38 of the screen.

The lower end of the head 10 is provided with a closure plate 39 in the center of which is an opening 40 and the opening is adapted to be closed by a ball 41 positioned to coact with a valve seat 42 at the upper end of the opening 40. The valve element or ball 41 is positioned in a cage or wall having a cap 43 and the cage is provided with a threaded cap 44, the end of which is provided with openings 45.

The head 10 is positioned in a cavity 46 below the lower end 47 of a section 48 of the well casing 13, and the upper end of the casing is threaded into a iiange 49 on the lower end of the packing gland 12, the upper end of which is provided with a nut Sti-that is positioned to urge packing 51 against the surface of the pipe or tube 11 to seal the upper end of the well casing.

With the parts assembled as shown and described, acid or other fluid discharged by the pump 14 is adapted to v reservoir 18.

to the tube 11 and downwardly through the well casing to the head where the acid is discharged through the orifices 33 against the formation 34, breaking down the formation andthe 'mixtureis returned through the well casing,V as indicated Y' bytheV arrows; Vwhereby'pwith""the valve 29 open'the-mixture'passes throughthe'connectio 27 in thenipple 20 to the' reservoir 18: f

With this arrangement of valves and pipes or tubing, the directionof travel of the acid or other'uid may readily be reversed by closing th'e valve 16 and opening the valve 25 and by closing the valve 29 and opening the valve 22. With the valve 25 opened, Vthe discharge of the pump 14l passes through the connection 24 to the connection `27 and from the 'connection 27; into the well casing '131w'ith the acid passing downwardly through 'the valve formed with the ball 41 and returning upwardly through the'pipe ort'tube 11 wherein lwith`the valve 16 closed the iiuid passes through the end ofV the section 17 to the section 21 and-with the valve 22 open the-fluid passes into the Itv will be understood that modifications, within the scope of the 'appended claim, may be made in the design and arrangement of the parts without departing from the spirit of the invention.

What is claimed is:

In a well acidizer, the combination which comprises a valve assembly including a cylindrical body having a base with an extended peripheral flange on they lower end, an internally threaded hub on the upper end, bosses having openings therethrough on the outer surface and an inner cylindrical wall extended upwardly from said base, the openings through the bosses being extended laterally through the cylindrical body said base having an opening therethrough with a valve seat in the upper end positioned within said inner cylindrical wall, a ball within said inner cylindrical wall positioned to co-act with the valve seat for closing the opening through the base, a cap having openings therethrough threaded ou the upper end of the inner cylindrical wall, and a substantially semispherical perforated cage secured to the flange extended from the peripheraledg'e of the base, said assembly being adapted to be mounted on the inner well string of a well.

References Cited in the le of this patent Y UNITED STATES v PATENTS 

